Mold-forming apparatus



w. H. MILLSPAUGH "1.720.741

MOLD FORMING APPARATUS Filed Jan. 13, 1928 Fig.5

Fig. 1

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Patented July 16, 1929.

UNITED STATES WILLIAM H. MILLSPAUGH, OF SANDUSKY, OHIO, ASSIGNOB TO'THE MACHINERY 00., OF SANDUSKY, OHIO.

MOLD-FORMING APPARATUS.

Application filed January s, 1928. Serial m. 240,461.

widely practiced methods where hollow ar-- ticles are to be produced is that of using a core member so shaped as to completely fill the space which is to be left hollow. A simple illustration is that of a pipe. In such a case, the outer member which receives the lining, as a matter of convenience, is tubular or cylindrical with an interior diameter equal to the exterior diameter of the refractory lining, as finally completed. When the thickness of the lining has been determined, a core plug is constructed havin a diameter equal to the diameter of the cy 1ndrical bore of the refractory lining. The plug is of approximately the length of mold. The lower end is centered in a suitable plate which closes the bottom of the shell in which the lining is formed. The refractory material is then suitably rammed in the annular space between the outer shell and core plug. 11 order to produce a refractory mold lining or wall of uniform thickness throughout, it is necessary to maintain the ramming core accurately in concentric position relatively to the shell or-' other member which contains the lining.- Again, in centrifu al casting, these molds are rotated at a h1 h rate of speed. Perfectl symmetrical distribution of the weight 0 the mold relatively to the axis of rotation, therefore, is a very important factor. Likewise, in the production of pipe or other 0 lindrical objects, ac- 45 curate parallelism of t e walls relatively to the longitudinal axis of the object is-essential. Necessarily, correspondin accuracy as to parallelism of the inner wa l of the refractory lining and its longitudinal axis must'exist, to reproduce the corresponding relation in the object cast. Heretofore, the great difficulty in applying the refractory lining has been to accurately maintain this parallelism. As the lining is rammed, the

plug inclines to a greater or less degree toward one side and from the other. Instead of being concentric it becomes more or less eccentric. The resulting lining takes a corresponding eccentric form, increasing in thickness on one side and correspondingly decreasing at a oint diametrically opposite.

The main ob ect of the present invention is to overcome the above and other objections and provide a simple, efiicient, compact and economical means whereby perfect accuracy of parallelism may be maintained from start to finish of the ramming operation.

Generally speaking, the invention comprlses a core plug of a comparativel short length relatively to the length of the nished mold and provided with devices whereby both its upper and lower ends ma be. ac? curately spaced from the inner wa l of the shell which receives the lining, during the progressive ramming of the mold, together with a coo rating adjustable bottom member which is adapted, in any adjusted position, to engage the lower end of the'core plug and maintain said plug in central position at the beginning of the ramming oper ation. This short core plug, of course, 'cooperates with the refractory lining, being raised, progressivel as the lining is rammed and, according to best practice, more than half of the plug remaining within the rammed portion, So that after the plug has left the bottom member its lower end is still efiiciently guided by the rammed lining while the upper end is as accurately guide by the devices carried by the upper end of the plug.

In'order to more clearly disclose the con-- str'uction, operation and use of the invention, reference should be had to the accompanying drawing forming part of the present application. Throughout the several figures of the drawings like reference characters indicate the same parts in the different views. L

In the drawings Fig. 1 is a central vertical CI'OSS'SOClElOIl through a cylindrical mold, partly ammed, and showing an adjustable bottom 'plate in position;

Fig. 2 is a top plan view of Fig. 1; and Fig. 3 is a fragmentary cross sectional view, showing spaclng means.

Referring to the drawings in detail, 1 indirarnn a mnxmn the mounting of the upper cates the outer member, usually of metal, and when pipe or other tubular castings are to be made, of corresponding tubular form. The

refractory lining of any of the usual and Well known mixtures is applied to the inner surface to the desired thickness and suitably rammed.

In order to have a perfectly uniform thickness or layer of refractory material a filling block or core plug 2 is provided. It is so constructed and proportioned that, when ac curately centered about the longitudinal axis of the shell 1, it will leave a peripheral space between the shell and corresponding plug wall equal in radial thickness to the thickness of the lining desired. In the particular instance illustrated a pipe or similar cylindrical mold is used. Therefore the plug 2 must be disposed accurately concentrically within the mold and spaced therefroma distance equal to the desired mold wall thickness. To maintain accurately, this relative position during the ramming operation, the lower end of the plug is provided with a short tapered frustroconical extension 3. This extension is designed to pass through a cooperating central opening 4 in the stop-0E plate 5. Preferably, the stop-oft plate 5 is made adjustable, longitudinally, within the shell 1. One simple and eflicient way of effecting this adjustment is by set screws. or the like 6 passed through the peripheral wall of the plate and taking against the inner wall of shell 1.

The upper radial face of the plug is provided with a plurality of laterally extending slide-ways, grooves or channels 7 in each of which is adj ustably slidably mounted a plate, bar, or other element 8 adapted to be fixed or definitely set or locked in various adjusted positions by one or more clamping or binding screws 9 or the like. In use, each of the bars or the like 8 will be moved in its channel until its outer or free end projects beyond the longitudinal wall of plug2 a distance equal to the width of the peripheral space between the plug and shell wall, and they are then all clamped. In such adjusted ositions, the outer free ends of the plates Wlll just engage or contact with the inner wall of shell 1. Thus, in the very first stage of the operation, the lower end of plug 2 will be accurately and positively centered by cooperation between the elements 3 and 5, while the upper end will be as accurately and positively centered by the plates 8. Now, the ramming of the refractory is started and completed to a point near the top of the plug. When this point is reached, the plug is drawn u by a hook 10 in the center of the top, by which any suitable lifting mechanism may be engaged. In the preferred method, the plug will be drawn only a comparatively short distance outwardly one half of its length. Thus, though the centering extension 3 will be drawn up out of the from the rammed lining-less than opening 4 of plate 5, the plug body 2 will remain in sliding engagement throughout its lower half or two-thirds with the cooperating inner face of the refractory lining. This contact will serve the same purpose for the lower end of the plug, in the progressive upward movements of the plug as successive portions are rammed, as the elements 3, 4 and 5 at the be inning 'ofthe operation.

@bviously, the stop plate 5 may be set and secured at any point in the length of shell 1 and when so set or adjusted, will serve as the starting point for properly centering the plug tion.

It is to be understood, of course, that the body in the beginning of the ramming operasingle construction illustrated in the drawings is purely illustrative and that many changes may be made in the construction, arrangement, and disposition of the several parts of the invention, within the scope ofthe appended claims without in any degree departing from the field and scope of the invention and it is meant to include all such within this application.

Having described my invention, what I claim and desire to protect by Letters Patent 1s 1. A mold forming device comprising, an outer tubular element adapted to receive a refractory lining, a core plug of less length than said tubular element, and means for maintaining said plug in spaced relation throughout its length within said tubular element relatively tothe same, said means being adapted to be positioned entirely within said tubular element.

2. A mold forming device comprising, an outer tubular element adapted to receive a refractory lining, a core plug of less length than said tubular element, means for maintaining the lower end of said plug in spaced relation relatively to said tubular element, and means for maintaining the upper end of said plug in similar spaced relation, both said means being ada ted to be positioned entirely within. said tuliular element.

3. A mold forming device comprising, an outer tubular element adapted to receive a refractory lining, a core plug of less length than said tubular element, means for closing the lower end of said tubular element and for centering. the lower end of said plug, and means for centering the upper end of said plug, said last mentioned means being adapted to be positioned entirely within said tubular element.

4. A mold forming device comprising, an outer tubular element adapted to receive a refractory lining, a core plug of less length than said tubular element and adapted to be advanced progressively within said element during the ramming operation, means for maintaining the lower part of said plug in central position at all times, and means for maintaining the upper end of said core plug in central position, both said means being adapted to be positioned entirely within said tubular element.

5. A mold forming device comprising, an outer tubular element adapted to receive a refractory lining, a core plug of less length than said tubular element and adapted to be advanced progressively within said element during the ramming operation, means for maintaining the lower part of said plug in central position at all times, means carried by the upper end of said core plug and adapted to engage said tubular element to space said core plug thereform, said means being adapted to be positioned entirely within said tubular element and means for securing said last named means in adjusted positions.

6. A mold forming device comprising, an outer tubular element adapted to receive a refractory lining, a core plug adapted to be advanced progressively within said element during the ramming operation, means for maintaining the lower part of said plug in central position at all times, means carried by the upper end of said core plug and adapted to engage said tubular element to space said core plug therefrom, and means for securing said last named means in adjusted positions.

7. A mold forming device comprising, an outer tubular element adapted to receive a refractory lining, a core plug of less length than said tubular element and adapted to be advanced progressively within said element during the ramming operation, means for maintaining the lower part of said plug in central position, means for selectively securing said means at various points longitudinally within said tubular element, and means for centering the upper end of said plug.

8. A mold forming device comprising, an

outer tubularelement adapted to receive a refractory lining, a core plug of less length than said tubular element means for maintaining the lower end of said plug in spaced relation relatively to said tubular element, and radially adjustable means for centering the upper end of said plug.

9. A mold forming device comprising, an outer tubular element adapted to receive a refractory lining, a core plug, of less length than said tubular element, means for maintaining the lower end of said lug in spaced relation relatively to said tu ular element, and radially adjustable means for centering the upper end of said plug said means being carried by the upper end of said plug.

10. A mold forming device comprising an outer tubular member adapted to receive a refractory lining, a core plug of less length than said tubular member having a central projection extending from its lower end and adapted to be advanced progressively within the tubular member during the ramming operations, a stop-ofl' plate constructed with a central opening into which said projection fits, and centering fingers projecting radially from the upper end 0 said plug.

11. A mold forming device comprising an outer tubular member adapted to receive a refractory lining, a core plug of less length than said tubular member having a central projection extending from its lower end and adapted to be advanced progressively within the tubular member during the ramming operation, a stop-ofl' plate constructed with a central opening into which said projection fits and means for selectively securing said stop-oil plate at various points longitudinally within said tubular member.

Signed at Sandusky, county of Erie, State of Ohio, this 9th day of J anuary, 1928.

WILLIAM H. MILLSPAUGH. 

